experiment wit Lee Gels,
stick them on the original diffuser or directly on the port wit some removable rubber-sticks or buis a holder for them.
I just received the INON Color Correcting Diffuser for my Z-240 and it looks as they work well.
Chris

To help in answering your question accurately haring we need to know what Ikelite strobes which you are using and what effect you are trying to achieve. Ikelite Ds125/160/161 strobes have a colour temperature of 4800K which gives a warmer effect to shots, especially wide angle. Thats why you see alot of wide angle photographers use the bigger Ikelite strobes for this purpose. The Ikelite DS50/51 has a colour Temperature of 5700K and the Inon Z240 have a 5500K temp which gives a whiter light which gives the images a cooler feel. The higher temp of the Inon z240's see alot of people use Colour correcting diffusers/filters on the strobe to lower the temperature and give a warmer feeling for wide angle. On the other hand my experience with the Ikelite's with the 4800K temp give a more orange tint to macro images. I adjust the colour temp in post processing or sometimes just a fine adjustment in colour settings for my Ikelite Ds161 and macro shots.